X-ray tetra

Pristella maxillaris

Translucent silver body with yellow, black and white fin markings

In the natural colour form, the strongest markings are on the dorsal and anal fins, with reddish colour on the tail. Gold and albino forms look different.

Adult length: Up to 4.5 cm (standard length, without the tail fin)
Water temperature: 22–28 °C
pH: 6–7.5
Hardness: 2–20 dGH

Avoid large or domineering companions. A translucent body does not mean the fish needs less food. The source suggests softer, more acidic water for breeding. This is not a requirement to target the lowest everyday care values or change water chemistry abruptly.

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Appearance and identification

Compared with the lemon tetra, the natural form has a more silvery, translucent body and reddish tail. Use normal live-fish references as well as this illustration when identifying fish. Size sources use different measurements: Seriously Fish lists 4.5 cm SL, while FishBase lists 4.5 cm TL. These are not interchangeable.

Same-species behaviour

The source recommends at least six, preferably ten or more of the same species.

Space requirements

The source recommends a footprint of at least 60 × 30 cm. Leave swimming space between planted areas; this is not a fixed stocking allowance.

Diet and feeding

Offer small flakes or granules with appropriately sized live or frozen foods.

Compatibility limits

Quiet individuals can be outcompeted by very active companions. Shrimp compatibility has not been verified.

Aquarium environment

Plant cover and open swimming room can coexist. A planted display does not require converting the aquarium to blackwater.

Sources

www.seriouslyfish.com ↗ 2026-10-21

researcharchive.calacademy.org ↗ 2026-10-22